Pencil sharpener



pg, 1929, R. E. V W !IGHT PENCIL SHARPEP IER Filed Aug. 13, 1927Patented Apr. 2, 1929.

UNITED STATES I 1,707,890 PATENT OFFICE.

RICHARD ERNEST WRIGHT, OF CAPE TOWN, CAPE OF GOOD HOPE, SOUTH AFRICA.

PENCIL SHARPENER.

Application filed August 13, 1927, Serial No. 212,769, and in GuatBritain September 21 1926.

This invention relates to an improved type of pencil sharpener of thekind in which a safety razor blade of wafer type is employed as thesharpening blade.

Generally in this kind of pencil sharpener the blade is clamped orsecured on a base having a holder such as a slotted conical tube forthe'rcception of the end of the pencil and sharpening is effected byrotating the pencil against the edge of the blade. Sometimes the bladeshave been mounted in a pencil sharp ening machine so as to revolve withrespect to the pencil.

According to this invention, the sharpener comprises a shaped baseadapted for the clamping thereto of a safety razor blade in such angularrelation to a guide on the base that the pencil may be sharpened bydrawing it over the base in engagement with the guide. The base isadapted for supporting the blade against vertical pressure withoutinterfering with the cutting operation and is suitably provided withshoulders for determining the depth of the cut and with side walls forguiding the pencil into gradual contact with the edge of the blade. Theblade is secured by a top plate which is of such a construction as tohold the'blade rigidly without interfering with the cutting operationand the mounting and fixing means suitably are so constructed anddisposed as to enable the pencil to be drawn gradually against the fineedge of the blade to produce a distribution and regulation of thecutting strains suitable for enabling these strains to be withstood bythe blade.

The invention is illustrated in the accompanying drawing in which Figure1 is a plan of the sharpener completely assembled.

Figure 2 is a longitudinal section, along th line 22 on Figure 1.

Figure 3 is a side elevation of the sharpener.

- Figure 4 is an end view of the sharpener.

Figure 5 is a plan of the sharpener with top plate and clamping boltremoved.

Figure 6 is aplan of the base of the sharpener with the top plate,clamping bolt, and blade removed.

In the above figures A is the base made of brass or other suitable metalshaped as shown to allow a space under the edge of the blade, and havingtapering shoulders B of the form and in the position shown, along whichthe end of the pencil is drawn in the process of sharpening.

The base A has two bulges C over which the holes in a safety razor bladecan fit, and which correspond with similarly placed depressions in thetop plate F. D is a hole through the base A, through which the clampingbolt G can pass. E is a safety razor blade of, the wafer type which fitsover the bulges C. The metal top plate F which holds the razor blade inposition on the base A, has a hole in its centre through which theclamping bolt G passes, and on this clamping bolt is screwed a nut H forclamping all the parts rigidly together.

The device is operated as follows The end of the pencil is drawn alongone or the other of the shoulders B, the outer side wall K or K of thebase forcing it gradually against the cutting edge of the obliquelydisposed blade which removes a shaving off the pencil. The shoulder Bdetermines the depth of the cut and as the gradually forced by the sidewall against the edge of the blade, owing to the latter being obliquelymounted with respect to the side wall, it will be seen that there is agradual application of the cutting pressure which increases as thepencil passes along the blade resulting in a distribution and regulationof the cutting strains such as to enable the blade to take these strainswithout breaking or buckling unduly. The shoulder B narrows gradually(to allow shavings to fall from the pencil) and supports the tip of theblade in the event of downward pressure upon the pencil.

After the completion of the stroke the penoil is turned slightly in thefingers, and again drawn across the blade in a similar manner, and so onuntil the required point is obtained.

The shavings are neatly deposited below the blade. The length of pointis varied at will by raising or lowering the hand holding the pencil.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is 1. In a pencil sharpener, a base having a pair oflongitudinal channels opening in one face of said base defining a midrib and side edges, the latter extending above the level of said mid ribto form pencil guides, said mid rib being provided with means diagonallyarranged for orienting a double edge wafer pencil is only bladediagonally with resp ct to said chan nels, and means for clamping saidblade in placeysaid'base being of such width that the wafer bladeextends substantially across said channels.

2. Inal'pencil'sharpene'r as clain'ied inclaini 1, the channels taperingtoward one end and being reversely arranged with respect to each other.

3. In a pencil sharpener, a base having a channel opening in one facethereof defining a blade support on one side and a pencil guide on theother said pencil guide being of greater elevation from the bottom ofsaid channel than said blade support, means on said blade support forsecuring a blade diagonally,said

base being of such width that said blade 6X-- tends substantially acrosssaid channel.

In testimony whereof I have aifixed Iny SlgIliLtllIB;

R. E. WRIGHT.

